use crate::prelude::*;
use crate::ecs::ThrustEvent;
use crate::server::ConnectedNetworkEntity;

pub fn server_thrust_plugin(app: &mut App) {
    app
        .add_systems(Update, process_thrust_events);
}

pub fn process_thrust_events(
    mut events: MessageReader<FromClient<ThrustEvent>>,

    clients: Query<&ConnectedNetworkEntity>,
    q_ls_me: Query<Entity, With<crate::ecs::Me>>,
) {
    for FromClient {
        client_id,
        message: event,
    } in events.read()
    {
        let player_hearty_entity = match client_id {
            ClientId::Client(client_entity) => {
                let ConnectedNetworkEntity {
                    game_entity: player_hearty_entity,
                } = clients.get(*client_entity).unwrap();
                player_hearty_entity
            },
            ClientId::Server => &q_ls_me.iter().next().unwrap()
        };
        let thrust_solution = &event.0;
        if !thrust_solution.converged { return };
        /* TODO: @tm85: have fun!
           TODO: The ThrustSolution contains a set of thrusters that should be on.
           TODO: All other thrusters should be off.
           TODO: If a thruster should be on, apply it's force vector at it's point
           TODO: (RigidBodyForces::apply_force_at_point,
           TODO: note this is worldspace!! [GlobalTransform is your friend])

           TODO: Note that this is only an event handler, and will only run
           TODO: when the client sends us a NEW thrust solution.

           TODO: You probably want to add a Component to the player entity (player_hearty_entity,
           TODO: it's also the hearty part entity) that stores the current ThrustSolution
           TODO: and applies it every tick, since avian's ExternalForces only apply for a single
           TODO: physics tick and must be applied every tick to be continuous.
           TODO: Hint: you probably want a mut commands: Commands in this system,
           TODO: and then insert a component with commands.entity(hearty).insert(YourNewComponent)

           TODO: To do this, create a new system (e.g. apply_thrust) or something, and apply thrust
           TODO: there, every tick (Update). Register it with the plugin above.

           TODO: I'll leave you to that. Have fun! ping me if you've got questions, I'll be up
           TODO: a while so can help you decipher the attachment system if need be.

           TODO: Overall, your goal is:
           TODO: - find all parts in the ship (hint: query for Parts on the ship (hearty))
           TODO: - for each part, find all thrusters (hint: query for PartThrusters on the part)
           TODO: - for each thruster, if it's on (check if it's in the player's current thrust soln)
           TODO: - apply a force at the correct point
           TODO: Much of the same logic is done in the client counterpart, to calculate effective
           TODO: force for the solver. Take a look at client::ship::thrusters.
           TODO: Note that relationship components (eg Parts, PartThrusters) wont exist if there are
           TODO: no children - eg hearty won't have Parts if nothing is attached, a part won't have
           TODO: PartThrusters if it has no thrusters.
           TODO: Handle this with Option<&Component> in the query
         */
    }
}